Gust effect factor ASCE 7-05

Gust effect factor ASCE 7-05

Gust effect factor ASCE 7-05

I am calculating the wind loading on a flexible structure and need to calculate the gust effect factor per section 6.5.8.2 and have hit a road block. I have determined n for the three cases needed to calculate Rh, Rb and RL. Equation 6-13a is for n > 0, and Equation 6-13b is for n = 0. In all three cases my calculated values for n are less than 0. What do I use to determine Rh, Rb and RL for this condition. I have doubled checked my values for n and they check. Any help will be greatly appreciated.